213 research outputs found
Development of a simple, self-contained flight test data acquisition system
The flight test system described combines state-of-the-art microprocessor technology and high accuracy instrumentation with parameter identification technology which minimize data and flight time requirements. The system was designed to avoid permanent modifications of the test airplane and allow quick installation. It is capable of longitudinal and lateral-directional stability and control derivative estimation. Details of this system, calibration and flight test procedures, and the results of the Cessna 172 flight test program are presented. The system proved easy to install, simple to operate, and capable of accurate estimation of stability and control parameters in the Cessna 172 flight tests
Wing mass formula for twin fuselage aircraft
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76666/1/AIAA-46261-468.pd
Study on a camber adaptive winglet
Morphing structures are devices intended to be implemented in specific parts of the aircraft such to improve some aspects of the flight such as performance and maneuverability. More specifically for the wings, the in flight capability of adaptation of airfoil profile and control surfaces bring possibility to the aircraft operate at optimum performance condition during all flight phases. Morphing structures can only lead to optimal flight maneuverability and performance conditions if the morphed geometry leads to an improved flight condition. Aiming at the reduction of the lift induced drag in all flight phases, this research focus on the application of the genetic optimization algorithm for the definition of the camber section of an winglet. This research proposes the optimization at four different flight phases namely: climb, heavy cruise, mid cruise and light cruise. BLWF – a full potential equation solver coupled with 3D boundary layer modelling – is adopted in the aerodynamic performance, e.g. lift and drag ratio, calculation. A conventional genetic algorithm is adopted in the optimization of the camber of the airfoil composing the winglet. This paper describes the optimization procedure and compares geometries showing that the in flight change of the winglet geometry can sensibly contribute to the improvement of the aircraft performance reducing the fuel consumption
Cross-Cultural Measurement Invariance in the Personality Inventory for DSM-5
The validity of cross-cultural comparisons of test scores requires that scores have the same meaning across cultures, which is usually tested by checking the invariance of the measurement model across groups. In the last decade, a large number of studies were conducted to verify the equivalence across cultures of the dimensional Alternative Model of Personality Disorders (DSM-5 Section III). These studies have provided information on configural invariance (i.e., the facets that compose the domains are the same) and metric invariance (i.e., facet-domain relationships are equal across groups), but not on the stricter scalar invariance (i.e., the baseline levels of the facets are the same), which is a prerequisite for meaningfully comparing group means. The present study aims to address this gap. The Personality Inventory for DSM-5 (PID-5) was administered to five samples differing on country and language (Belgium, Catalonia, France, Spain, and Switzerland), with a total of 4,380 participants. Configural and metric invariance were supported, denoting that the model structure was stable across samples. Partial scalar invariance was supported, being minimal the influence of non-invariant facets. This allowed cross-cultural mean comparisons. Results are discussed in light of the sample composition and a possible impact of culture on development of psychopathologyPreparation of this
manuscript was supported by Grant PSI2017–85022-P (Ministerio de Ciencia, Innovacion ´ y Universidades, Spain) and the UAM-IIC Chair "Psychometric Models and
Applications
Surrogate Models and Mixtures of Experts in Aerodynamic Performance Prediction for Mission Analysis
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140436/1/6.2014-2301.pd
A Systematic Methodology for Populating the Aircraft Thermal Management System Architecture Space
Presented at AIAA SCITECH 2021The aircraft thermal management system functions to provide suitable working conditions for pilot, crew, passengers, and the other aircraft systems. The additional weight, drag and power consumption caused by it greatly influences the performance of the aircraft. However, due to rising heat load of emerging novel aircraft concepts, traditional design approaches which rely on data and empirical equations may not apply to the future thermal management systems. Many existing literature which tried to identify the optimal thermal management system architectures only considered limited architecture space where the candidates were pre-selected in terms of experience or intuition. Therefore, viable but non-intuitive architectures may not be included in the design space. To fill this gap, this paper proposes a behavior-based backtracking methodology to systematically populate the architecture space by enumerating both intuitive and non-intuitive architectures. Thermal management requirements for traditional and novel configurations are used to generate the architectures. By comparing the generated architectures with existing ones, this paper validates that the proposed methodology is capable of generating both intuitive and non-intuitive architectures
Profiles of Parental Burnout Around the Globe: Similarities and Differences Across 36 Countries
Parental burnout (PB) is a pervasive phenomenon. Parenting is embedded in cultural values, and previous research has shown the role of individualism in PB. In this paper, we reanalyze previously collected data to identify profiles based on the four dimensions of PB, and explore whether these profiles vary across countries' levels of collectivistic-individualistic (COL-IND) values. Our sample comprised 16,885 individuals from 36 countries (73% women; 27% men), and we used a latent profile approach to uncover PB profiles. The findings showed five profiles: Fulfilled, Not in PB, Low risk of PB, High risk of PB and Burned out. The profiles pointed to climbing levels of PB in the total sample and in each of the three country groups (High COL/Low IND, Medium COL-IND, Low COL/High IND). Exploratory analyses revealed that distinct dimensions of PB had the most prominent roles in the climbing pattern, depending on the countries' levels of COL/IND. In particular, we found contrast to be a hallmark dimension and an indicator of severe burnout for individualistic countries. Contrary to our predictions, emotional distance and saturation did not allow a clear differentiation across collectivistic countries. Our findings support several research avenues regarding PB measurement and intervention
Use of prescription stimulant for Attention Deficit Hyperactivity Disorder in Aboriginal children and adolescents: a linked data cohort study
A systematic review and critical assessment of incentive strategies for discovery and development of novel antibiotics
Despite the growing threat of antimicrobial resistance, pharmaceutical and biotechnology firms are reluctant to develop novel antibiotics because of a host of market failures. This problem is complicated by public health goals that demand antibiotic conservation and equitable patient access. Thus, an innovative incentive strategy is needed to encourage sustainable investment in antibiotics. This systematic review consolidates, classifies and critically assesses a total of 47 proposed incentives. Given the large number of possible strategies, a decision framework is presented to assist with the selection of incentives. This framework focuses on addressing market failures that result in limited investment, public health priorities regarding antibiotic stewardship and patient access, and implementation constraints and operational realities. The flexible nature of this framework allows policy makers to tailor an antibiotic incentive package that suits a country’s health system structure and needs
Profiles of Parental Burnout Around the Globe: Similarities and Differences Across 36 Countries
Parental burnout (PB) is a pervasive phenomenon. Parenting is embedded in cultural values, and previous research has shown the role of individualism in PB. In this paper, we reanalyze previously collected data to identify profiles based on the four dimensions of PB, and explore whether these profiles vary across countries’ levels of collectivistic-individualistic (COL-IND) values. Our sample comprised 16,885 individuals from 36 countries (73% women; 27% men), and we used a latent profile approach to uncover PB profiles. The findings showed five profiles: Fulfilled, Not in PB, Low risk of PB, High risk of PB and Burned out. The profiles pointed to climbing levels of PB in the total sample and in each of the three country groups (High COL/Low IND, Medium COL-IND, Low COL/High IND). Exploratory analyses revealed that distinct dimensions of PB had the most prominent roles in the climbing pattern, depending on the countries’ levels of COL/IND. In particular, we found contrast to be a hallmark dimension and an indicator of severe burnout for individualistic countries. Contrary to our predictions, emotional distance and saturation did not allow a clear differentiation across collectivistic countries. Our findings support several research avenues regarding PB measurement and intervention
- …